Modular units

GeneralitiesSafety of people
PE50798 61058N
61012N
DE53514
PE57841
SF1 circuit breaker
Evolis circuit breaker
Evolis lateral version
Vacuum type contactor
AMTED398078EN.indd
By switchgear
SF6 circuit breaker: SF1
b Gas tightness
The SF1 circuit breaker is made up of three separate poles mounted
on a structure supporting the operating mechanism. Each pole-unit houses
all the active elements in an insulating enclosure fi lled with gas to a relative pressure
of 0.5 bar (500 hPa) for 24 kV and 2 bar (2000 hPa) for 36 kV. It satisfi es “sealed
pressure system” requirements and seal tightness is always checked in the factory.
b Operating safety
Accidental over-pressures are eliminated by the opening of the safety membrane.
Contacts closed Precompression Arcing period Contacts open
Vacuum type circuit breaker: Evolis
b Vacuum tightness
The Evolis circuit breaker comprises three separate pole units fi xed on a structure
supporting the control mechanism. Each pole encloses all of the active parts in an
insulating enclosure, under vacuum, and its vacuum tightness is systematically
checked in the factory.
b Operating safety
The magnetic fi eld is applied along the contact axis of the vacuum type circuit breaker.
This process diffuses the arc in a regular manner with high currents.
It ensures optimum distribution of the energy along the compact surface
so as to avoid local hot spots.
The advantages of this technique:
v a simplifi ed vacuum type circuit breaker which is consequently very reliable,
v low dissipation of arcing energy in the circuit breaker,
v highly effi cient contacts which do not distort during repeated breaking,
v signifi cant reduction in control energy.
Vacuum type contactor
b Vacuum tightness
Vacuum contactor comprises three separate poles fi xed on a structure supporting
the control mechanism. Each pole encloses all of the active parts in an insulating
enclosure under vacuum and its vacuum tightness is checked in the factory.
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